It would be a mistake to call the Line 6 JM4 just another loop pedal. With the amount of features that are jam-packed in this unit, it’s definitely a guitar player’s workstation. Besides its looping capabilities, the JM4 Looper is an amp modeler, effects unit, and composing/practicing tool, all in one.

Within its rugged construction, it houses 12 Line 6 amp models from clean to “insane.” The seven Smart Control FX include Chorus/Flanger, Phaser, Tremolo, Reverb, and tap tempo effects such as Delay, Tape Echo and Sweep Echo. Effects for the independent vocal/aux input include 3-band EQ, Compressor, Delay and Reverb. An integrated tuner is very useful to check your tuning in between jamming. There are plenty of presets to make a guitarist happy: more than 200 artist-created presets, more than 150 song-based presets, and 36 user-programmable presets.

The ins and outs of the JM4 include: separate instrument, aux and mic inputs, as well as an input for a CD or MP3 player, and outputs for an amp, stereo headphones and stereo line out. A Master Volume knob controls the output, and there is also a Trim knob to adjust the gain of the mic input.

The Looper can work just like any other loop pedal, by looping and stacking tracks from just one instrument. However, it also features over 100 “Endless Jam” tracks and drum grooves for you to play along and create loops with. There are many different musical styles to jam with—from metal to country and everything in between. These tracks aren’t just sterile MIDI tracks with fake-sounding instruments, they’re actual recordings by top LA and Nashville session players. These high-quality grooves sound great and they’re fun to jam with. It sounds as if you’re playing with a real band, not a Casio keyboard! A fair warning: going through these tracks and playing along can be very addictive (see clips 1 & 2). I easily spent a couple of hours jamming along with them !

You can save up to 100 CD-quality recordings internally (totaling 24 minutes of recording time), and there is a slot for an SD card (sold separately) if you want to import and export loops and recordings. The JM4 supports up to a 2GB SD card, which is good for up to 6.5 hours of recorded jams. The looper has dedicated footswitches for Record/Overdub, Play/ Stop, Half Speed, and a handy Undo feature, should you wish to discard your last take or flubbed line.

Features, Features, Features!
As you can see, there are so many features on this unit that I didn’t know where to start exploring. I decided to check out the different amp models first. The basic amp model set consists of Clean, Twang, Blues, Crunch, Metal and Insane. I liked the fact that each different model has two variations—labeled “Red” and “Green.” For example, the Blues Red is inspired by a mix of a ’65 Marshall JTM45, a ’58 Bassman and a ’63 Fender Vibroverb and a Supro. The Blues Green is more like an early British rock tone, inspired by a fawn Vox AC30 with an expanded and updated tone control circuit. Each model can be tweaked with the Drive, Bass, Mid and Treble controls.

I’m a big believer in presets. I have no problem with companies that spend a lot of time and money to create good sounding presets— they do all the hard work for you! It’s a big time saver, and most of the time the presets are ideas that I would never come up with on my own. With the JM4, I was really impressed with the Artist presets. There are over 200 presets that were dialed in by a number of rock star guitarists—everyone from Albert Lee to INXS to Slipknot. The tonal variety was plentiful and there seems to be something for every taste. Some of the artists recreated the unique tones from their records, while others explored and created new sounds. I found every sound fresh and innovative, and they were fun to play with. Each of these presets can be modified and saved to one of the 36 User preset locations.

The Style presets are great as well. These tones are based on the top 200 guitar rock songs of all time, from the fifties all the way to today. For example, if you want the tone that Ritchie Blackmore had on “Smoke on the Water,” it’s here. If you want Prince’s clean sound from “Purple Rain,” it’s here also! The presets are actually labeled by the song names that these guitar tones are modeling. I had a great time scrolling through and playing these songs with tones and effects that are very similar to the originals (see clip 3).

Of course the main feature is the looper. The JM4 manual provides a couple of tutorials to get you up and running right away. I wanted to create a four-bar loop with drums as a foundation. I simply picked a groove from the drums menu, armed the guitar record button and pressed Record. The concept is simple: after you hit record, there is a count in, and then you play a phrase on your guitar for four bars. On the downbeat of bar five, hit Record again and it will loop back to the beginning. You have then set your four-bar phrase, which will loop over and over. To add another overdub, you simply press Record again and play, and hit the button again at the end of your phrase. You can then add additional overdubs for each repeat of the loop. You can also tap Undo if you don’t like a phrase you just recorded. In minutes you can become a loop master (see clip 4)!

The Final Mojo
The Line 6 JM4 is a useful tool for any guitarist. A casual or amateur guitarist will enjoy practicing and jamming with the JM4 and sharpening his or her skills. This is also a great tool for professional guitarists who want to keep their chops up in between gigs. The abundance of looping capabilities, tracks, sounds and effects will keep a guitarist busy and happy for hours!

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